Kalsiumsignal

Kalsiumsignal refers to the role of calcium ions (Ca2+) in cellular communication and regulation. Calcium is a critical intracellular messenger, meaning that changes in its concentration within a cell trigger a cascade of events. The concentration of free calcium in the cytoplasm is tightly controlled, with much higher concentrations typically stored in intracellular organelles like the endoplasmic reticulum and mitochondria, or outside the cell.

When a cell receives a signal, such as from a hormone or neurotransmitter, it can lead to a rapid increase in cytoplasmic calcium. This influx can occur through calcium channels in the cell membrane or by release from internal stores. The elevated calcium then binds to specific proteins, most notably calmodulin. This binding often activates other enzymes and proteins, leading to a variety of cellular responses.

These responses are diverse and include muscle contraction, neurotransmitter release, gene expression, cell growth and division, and apoptosis (programmed cell death). Because calcium signaling is so fundamental to so many cellular processes, dysregulation of calcium homeostasis is implicated in numerous diseases, including cardiovascular disorders, neurodegenerative diseases, and cancer. The precise spatiotemporal dynamics of calcium signals, such as localized calcium spikes or waves, are crucial for conveying specific information within the cell.